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Jun 2023 DOI 10.14302/issn.2377-2549.jndc-23-4615
A literature review was undertaken with a focus on 1) identifying the research gaps regarding CECs, 2) identifying the most common ones, and 3) identifying the typical analytical methods/technologies employed, for their analysis. A total of 214 papers were noted, with a total of 21 review articles (9.8%). Of this total, a surprisingly high number were from South Africa alone: 117 (54.7%), of which 44 (20.6%) reports were associated with South Africa’s Water Research Commission (WRC). The top three CECs research gaps were (decreasing rank: Number of “gaps”, %): 1) Toxicity/Risk/Impact (260, 21.5%), 2) Analysis/Tests/Methods (118, 9.8%) and 2) Future research/studies (118, 9.8%), and 3) Monitoring (89, 7.4%). The common classes of CECs that were reported on, were : (i) Chemical: pharmaceuticals, personal care products, steroids, chlorinated and brominated contaminants, PAHs, PCBs, phthalates, alkyl phenols, herbicides, organochlorine pesticides, engineered nanomaterials and (ii) “Microbiological”: antibiotic resistance genes, human enteric bacteria and viruses, microbial pathogens (e.g., E Coli, rotavirus, Crypto, etc.), infectious biological water contaminants (e.g., E Coli isolates), cyanobacterial blooms (Microcystis). Common test methods used for analysis of the chemical contaminants were found to be chromatography (gas, liquid)-mass spectrometry; for the microbial contaminants, they were culture-based methods, ELISA, fluorescence microscopy, qPCR, RT-qPCR, gel electrophoresis, Raman spectroscopy, and also chromatography (largely liquid)-mass spectrometry, were also used. Some proposals were additionally made to address the very common, significant research gaps noted in CECs research, especially the standardization of analytical chemical test methods, based on chromatography-mass spectrometry, for quantification.
Sep 2020 DOI 10.14302/issn.2575-1212.jvhc-20-3477
A total number of 100 samples from ten random broiler chicken carcasses (breast and thigh) were collected from an automatic poultry slaughtering plant in Ismailia city, Egypt. The mean values of Enterobacteriacae count were 5.9x104±9.7x103 cfu/g and 7.1x 104 ± 1.1x104 cfu/g for chicken breast and thigh samples respectively. The prevalence of E.coli were 12% and 9% breast and thigh samples examined, respectively. They are serologically identified as 33.35 and 22.2% O157:H7 (EHEC) , 16.6% and 11.1% O114:H21(EPEC), 16.6% and 33.3 %O127:H6 (ETEC) , 0% and 0% O126 (ETEC) and 33.3% and 0% O26 (EHEC) for breast and thigh samples, respectively. The incidence of E.coli O157:H7 was 100% in both serological and PCR methods from biochemical positive E.coli samples. Culture is specific and cheap whereas PCR is sensitive and expensive, hence, we recommend both culture and molecular methods, which improve sensitivity and specificity, to enhance detection of foodborne pathogens including E.coli.
Oct 2021 DOI 10.14302/issn.2690-0904.ijoe-21-3966
The impact of the environment on the development of non-communicable chronic diseases has gained prominence in recent years. In this context, a new chemical exposure assessment strategy is needed that is capable of revealing multiple exposures, as well as reflecting the cumulative interaction between such environmental contaminants in the biological system. From this perspective, metabolomics emerges as a promising tool in this field of knowledge, since it is able to identify changes in metabolism and/or gene expression resulting from exposure to environmental factors. The aim of this study was to describe important concepts, as well as the steps that permeate the metabolomics analysis, and also to present some relevant works with the application of metabolomics in the assessment of chemical exposure. A literature review showed a significant increase in the use of metabolomics in environmental toxicology in recent years. This increase is mainly due to advances in analytical techniques and the improvement of data processing tools. However, this field of investigation remains little explored, especially with regard to the study of toxicity associated with chronic exposure to low levels of chemical agents. Thus, it is urgent that omic biomarkers can be used as a tool for decision-making, especially with a view to protecting, diagnosing and recovering human health.
Feb 2018 DOI 10.14302/issn.2379-7835.ijn-17-1872
Objective: To elaborate on the procedures undertaken to establish blood draws and cold chain for nutrition assessments. Setting: A total of 5,044 birth cohort households were enrolled and assessed using household questionnaires, anthropometry, and blood sampling to assess nutritional issues and exposures to environmental contaminants. The challenge was to obtain, transport, process, store, and analyze tens of thousands of serum samples obtained in sites that were often difficult to reach. Approach: Before enrollment began, 24 healthcare facilities in the North and Southwest of Uganda were assessed for suitability as local nodes for processing and storage. Equipment needs included functional centrifuges, refrigeration, ice machines, and -20oC freezers. Other important physical infrastructure included the presence of backup power (generator or solar generated) in the event of electricity failure. Once samples were obtained, they were transported within 5 hours to the facility laboratories, where serum was separated and aliquoted into properly labelled storage tubes and then frozen. Relevant Changes: At community level, our team visited households or small group of household members close to their homes to reduce on travel time hence contributed to high retention rates. Our immediate testing for anemia and malaria results benefited enrollees and enhanced community acceptance. By using Village Health Teams (VHTs), we could accommodate household preferences for the timing of sample collection. Our engagement with phlebotomists transformed their role from a simple service into active team members. Lessons Learned: Our first lesson was that in our setting, the success of this nutrition biological sampling system required community engagement and acceptance. By combining an immediately actionable set of tests (for anemia and malaria), and visiting cohort households, we greatly enhanced the success of the system.